/*
ID: bqi3431
PROG: island2
LANG: C++11
*/

#pragma GCC optimize ("O3")
#pragma GCC target ("sse4")

#include <bits/stdc++.h>
#include <ext/pb_ds/tree_policy.hpp>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/rope>

using namespace std;
using namespace __gnu_pbds;
using namespace __gnu_cxx;
 
typedef long long ll;
typedef long double ld;
typedef complex<ld> cd;

typedef pair<int, int> pi;
typedef pair<ll,ll> pl;
typedef pair<ld,ld> pd;

typedef vector<int> vi;
typedef vector<ld> vd;
typedef vector<ll> vl;
typedef vector<pi> vpi;
typedef vector<pl> vpl;
typedef vector<cd> vcd;

template <class T> using Tree = tree<T, null_type, less<T>, rb_tree_tag,tree_order_statistics_node_update>;

#define FOR(i, a, b) for (int i = (a); i < (b); i++)
#define F0R(i, a) for (int i = 0; i < (a); i++)
#define FORd(i,a,b) for (int i = (b)-1; i >= (a); i--)
#define F0Rd(i,a) for (int i = (a)-1; i >= 0; i--)
#define trav(a, x) for (auto& a : x)

#define mp make_pair
#define pb push_back
#define f first
#define s second
#define lb lower_bound
#define ub upper_bound

#define sz(x) (int)x.size()
#define beg(x) x.begin()
#define en(x) x.end()
#define all(x) beg(x), en(x)
#define resz resize

const int MOD = 1000000007;
const ll INF = 1e18;
const int MX = 100001;
const ld PI = 4*atan((ld)1);

template<class T> void ckmin(T &a, T b) { a = min(a, b); }
template<class T> void ckmax(T &a, T b) { a = max(a, b); }

namespace io {
    // TYPE ID (StackOverflow)
    
    template<class T> struct like_array : is_array<T>{};
    template<class T, size_t N> struct like_array<array<T,N>> : true_type{};
    template<class T> struct like_array<vector<T>> : true_type{};
    template<class T> bool is_like_array(const T& a) { return like_array<T>::value; }

    // I/O 
    
    void setIn(string s) { freopen(s.c_str(),"r",stdin); }
    void setOut(string s) { freopen(s.c_str(),"w",stdout); }
    void setIO(string s = "") {
        ios_base::sync_with_stdio(0); cin.tie(0);
        if (sz(s)) { setIn(s+".in"), setOut(s+".out"); }
    }
    
    // INPUT 
    
    template<class T> void re(T& x) { cin >> x; }
    template<class Arg, class... Args> void re(Arg& first, Args&... rest) { re(first); re(rest...); }
    
    void re(double& x) { string t; re(t); x = stod(t); }
    void re(ld& x) { string t; re(t); x = stold(t); }
    void re(cd& x) { ld a,b; re(a,b); x = cd(a,b); }
    
    template<class T1, class T2> void re(pair<T1,T2>& p) { re(p.f,p.s); }
    template<class T> void re(vector<T>& a) { F0R(i,sz(a)) re(a[i]); }
    template<class T, size_t SZ> void re(array<T,SZ>& a) { F0R(i,SZ) re(a[i]); }
    
    // OUTPUT 
    
    template<class T1, class T2> ostream& operator<<(ostream& os, const pair<T1,T2>& a) {
        os << '{' << a.f << ", " << a.s << '}'; return os;
    }
    template<class T> ostream& printArray(ostream& os, const T& a, int SZ) {
        os << '{';
        F0R(i,SZ) {
            if (i) {
                os << ", ";
                if (is_like_array(a[i])) cout << "\n";
            }
            os << a[i];
        }
        os << '}';
        return os;
    }
    template<class T, size_t SZ> ostream& operator<<(ostream& os, const array<T,SZ>& a) {
        return printArray(os,a,SZ);
    }
    template<class T> ostream& operator<<(ostream& os, const vector<T>& a) {
        return printArray(os,a,sz(a));
    }
    
    template<class T> void pr(const T& x) { cout << x << '\n'; }
    template<class Arg, class... Args> void pr(const Arg& first, const Args&... rest) { 
        cout << first << ' '; pr(rest...); 
    }
}

using namespace io;

int H,W;
bool done[1000][1000];
char g[1000][1000];
queue<pi> q;
bitset<1005> cover[1005][4];

int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1};

bool valid(pi x) {
    return 0 <= x.f && x.f < H && 0 <= x.s && x.s < W;
}

int numA(int a, int b) {
    int ans = 0;
    F0R(i,4) {
        pi z = {a+xd[i],b+yd[i]};
        if (!valid(z)) continue;
        ans += (g[z.f][z.s] == 'A');
    }
    return ans;
}

pi ad(pi a, int b) {
    b %= 4;
    return {a.f+xd[b],a.s+yd[b]};
}

bool isEmp(pi x) { 
    if (!valid(x)) return 1;
    return !done[x.f][x.s] && g[x.f][x.s] == '.';
}

bool isA(pi a) {
    return valid(a) && done[a.f][a.s];
}

void check(int a, int b) {
    if (!valid({a,b})) return;
    if (done[a][b]) return;
    bool ok = 0;
    if (numA(a,b) >= 3) ok = 1;
    F0R(i,4) {
        if (isA(ad({a,b},i)) && isA(ad({a,b},i+1)) && isEmp(ad({a,b},i+2)) && isEmp(ad({a,b},i+3)) && isEmp(ad(ad({a,b},i+3),i+2))) ok = 1;
    }
    if (!ok) return;
    done[a][b] = 1; q.push({a,b});
}

int main() {
    // you should actually read the stuff at the bottom
    setIO("island2"); 
    re(H,W); 
    F0R(i,H) F0R(j,W) {
        re(g[i][j]);
        if (g[i][j] == 'A') done[i][j] = 1;
    }
    F0R(i,H) F0R(j,W) check(i,j);
    while (sz(q)) {
        auto a = q.front(); q.pop();
        g[a.f][a.s] = 'A';
        FOR(i,-1,2) FOR(j,-1,2) check(a.f+i,a.s+j);
    }
    pi top = {-1,-1};
    F0R(i,H) F0R(j,W) if (done[i][j]) top = max(top,{i,j});
    pair<pi,int> cur = {{top.f+1,top.s},1};
    // auto TOP = ad({top.f+1,top.s},1);
    int ret = 0;
    while (!cover[cur.f.f+2][cur.s][cur.f.s+2]) {
        ret ++;
        cover[cur.f.f+2][cur.s][cur.f.s+2] = 1;
        // g[cur.f.f][cur.f.s] = '*';
        cur.f = ad(cur.f,cur.s);
        if (!isA(ad(cur.f,cur.s+1))) cur.s = (cur.s+1)%4;
        else if (!isA(ad(cur.f,cur.s))) {
            
        } else {
            assert(!isA(ad(cur.f,cur.s+3)));
            cur.s = (cur.s+3)%4;
        }
    }
    pr(ret);
    /*F0R(i,H) {
        F0R(j,W) cout << g[i][j];
        cout << "\n";
    }*/
    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?), set tle
    * do smth instead of nothing and stay organized
*/
